Wrap help text to the terminal width

Author: sgravrock

bin/jasmine.js

@@ -2,6 +2,7 @@
 
 const path = require('path');
 const os = require('os');
+const process = require('process');
 const Command = require('../lib/command');
 const Jasmine = require('../lib/jasmine');
 const ParallelRunner = require("../lib/parallel_runner");
@@ -11,7 +12,12 @@ const command = new Command(path.resolve(), examplesDir, {
   Jasmine,
   ParallelRunner,
   print: console.log,
+  terminalColumns: process.stdout.columns,
   platform: os.platform,
 });
 
-command.run(process.argv.slice(2));
+command.run(process.argv.slice(2))
+  .catch(e => {
+    console.error(e);
+    process.exit(1);
+  });

lib/command.js

@@ -27,7 +27,7 @@ const subCommands = {
 };
 
 function Command(projectBaseDir, examplesDir, deps) {
-  const {print, platform, Jasmine, ParallelRunner} = deps;
+  const {print, platform, terminalColumns, Jasmine, ParallelRunner} = deps;
   const isWindows = platform() === 'win32';
 
   this.projectBaseDir = isWindows ? unWindows(projectBaseDir) : projectBaseDir;
@@ -54,7 +54,8 @@ function Command(projectBaseDir, examplesDir, deps) {
         projectBaseDir,
         specDir: command.specDir,
         examplesDir: examplesDir,
-        print
+        print,
+        terminalColumns
       });
     } else {
       const options = parseOptions(args, isWindows);
@@ -66,7 +67,7 @@ function Command(projectBaseDir, examplesDir, deps) {
         }
 
         print('');
-        help({print: print});
+        help({print, terminalColumns});
       } else {
         await runJasmine(Jasmine, ParallelRunner, projectBaseDir, options);
       }
@@ -284,39 +285,90 @@ function installExamples(options) {
   );
 }
 
-function help(options) {
-  const print = options.print;
-  print('Usage: jasmine [command] [options] [files] [--]');
+function help(deps) {
+  const print = deps.print;
+  let terminalColumns = deps.terminalColumns || 80;
+
+  print(wrap(terminalColumns, 'Usage: jasmine [command] [options] [files] [--]'));
   print('');
   print('Commands:');
   Object.keys(subCommands).forEach(function(cmd) {
     let commandNameText = cmd;
     if(subCommands[cmd].alias) {
       commandNameText = commandNameText + ',' + subCommands[cmd].alias;
     }
-    print('%s\t%s', lPad(commandNameText, 10), subCommands[cmd].description);
+    print(wrapWithIndent(terminalColumns, lPad(commandNameText, 10) + '    ', subCommands[cmd].description));
   });
   print('');
-  print('If no command is given, jasmine specs will be run');
+  print(wrap(terminalColumns, 'If no command is given, Jasmine specs will be run.'));
   print('');
   print('');
 
   print('Options:');
-  print('%s\tRun in parallel with N workers', lPad('--parallel=N', 18));
-  print('%s\tRun in parallel with an automatically chosen number of workers', lPad('--parallel=auto', 18));
-  print('%s\tturn off color in spec output', lPad('--no-color', 18));
-  print('%s\tforce turn on color in spec output', lPad('--color', 18));
-  print('%s\tfilter specs to run only those that match the given string', lPad('--filter=', 18));
-  print('%s\tload helper files that match the given string', lPad('--helper=', 18));
-  print('%s\tload module that match the given string', lPad('--require=', 18));
-  print('%s\tstop Jasmine execution on spec failure', lPad('--fail-fast', 18));
-  print('%s\tpath to your optional jasmine.json', lPad('--config=', 18));
-  print('%s\tpath to reporter to use instead of the default Jasmine reporter', lPad('--reporter=', 18));
-  print('%s\tprint information that may be useful for debugging configuration', lPad('--verbose', 18));
-  print('%s\tmarker to signal the end of options meant for Jasmine', lPad('--', 18));
+
+  const options = [
+    { syntax: '--parallel=N', help: 'Run in parallel with N workers' },
+    { syntax: '--parallel=auto', help: 'Run in parallel with an automatically chosen number of workers' },
+    { syntax: '--no-color', help: 'turn off color in spec output' },
+    { syntax: '--color', help: 'force turn on color in spec output' },
+    { syntax: '--filter=', help: 'filter specs to run only those that match the given string' },
+    { syntax: '--helper=', help: 'load helper files that match the given string' },
+    { syntax: '--require=', help: 'load module that matches the given string' },
+    { syntax: '--fail-fast', help: 'stop Jasmine execution on spec failure' },
+    { syntax: '--config=', help: 'path to the Jasmine configuration file' },
+    { syntax: '--reporter=', help: 'path to reporter to use instead of the default Jasmine reporter' },
+    { syntax: '--verbose', help: 'print information that may be useful for debugging configuration' },
+    { syntax: '--', help: 'marker to signal the end of options meant for Jasmine' },
+  ];
+
+  for (const o of options) {
+    print(wrapWithIndent(terminalColumns, lPad(o.syntax, 18) + '    ', o.help));
+  }
+
   print('');
-  print('The given arguments take precedence over options in your jasmine.json');
-  print('The path to your optional jasmine.json can also be configured by setting the JASMINE_CONFIG_PATH environment variable');
+  print(wrap(terminalColumns,
+    'The given arguments take precedence over options in your jasmine.json.'));
+  print(wrap(terminalColumns,
+    'The path to your optional jasmine.json can also be configured by setting the JASMINE_CONFIG_PATH environment variable.'));
+}
+
+function wrapWithIndent(cols, prefix, suffix) {
+  const lines = wrap2(cols - prefix.length, suffix);
+  const indent = lPad('', prefix.length);
+  return prefix + lines.join('\n' + indent);
+}
+
+function wrap(cols, input) {
+  return wrap2(cols, input).join('\n');
+}
+
+function wrap2(cols, input) {
+  let lines = [];
+  let start = 0;
+
+  while (start < input.length) {
+    const splitAt = indexOfLastSpaceInRange(start, start + cols, input);
+
+    if (splitAt === -1 || input.length - start <= cols) {
+      lines.push(input.substring(start));
+      break;
+    } else {
+      lines.push(input.substring(start, splitAt));
+      start = splitAt + 1;
+    }
+  }
+
+  return lines;
+}
+
+function indexOfLastSpaceInRange(start, end, s) {
+  for (let i = end; i >= start; i--) {
+    if (s[i] === ' ') {
+      return i;
+    }
+  }
+
+  return -1;
 }
 
 function version(options) {

spec/command_spec.js

@@ -44,7 +44,7 @@ describe('command', function() {
       let output = "";
       return {
         print: function(str) {
-          output += str;
+          output += str + '\n';
         },
         getOutput: function() {
           return output;
@@ -565,6 +565,52 @@ describe('command', function() {
       });
     });
   });
+
+  describe('help', function() {
+    it('wraps text to the terminal width', async function() {
+      this.command = new Command(projectBaseDir, '', {
+        print: this.out.print,
+        terminalColumns: 50,
+        platform() {
+          return 'arbitrary';
+        }
+      });
+
+      await this.command.run(['help']);
+
+      const output = this.out.getOutput();
+      expect(output).toContain('version,-v    show jasmine and jasmine-core\n' +
+        '              versions\n');
+      expect(output).toContain('   --parallel=auto    Run in parallel with an\n' +
+        '                      automatically chosen number\n' +
+        '                      of workers\n' +
+        '        --no-color    turn off color in spec\n' +
+        '                      output\n' +
+        '           --color    force turn on color in spec\n' +
+        '                      output\n');
+      expect(output).toContain('The given arguments take precedence over options\n' +
+        'in your jasmine.json.\n' +
+        'The path to your optional jasmine.json can also be\n' +
+        'configured by setting the JASMINE_CONFIG_PATH\n' +
+        'environment variable.\n');
+    });
+
+    it('wraps text to 80 columns when the terminal width is unknown', function() {
+      this.command = new Command(projectBaseDir, '', {
+        print: this.out.print,
+        terminalColumns: undefined,
+        platform() {
+          return 'arbitrary';
+        }
+      });
+
+      this.command.run(['help']);
+
+      const output = this.out.getOutput();
+      expect(output).toContain('   --parallel=auto    Run in parallel with an automatically chosen number of\n' +
+        '                      workers\n');
+    });
+  });
 });
 
 // Adapted from Sindre Sorhus's escape-string-regexp (MIT license)